Tropical forest systems: A hydrological approach

This paper briefly examines the importance of considering the rates and magnitudes of water movement in the hillslope-river system of a tropical rainforest catchment. It is proposed that consideration of water movement is a fundamental component in understanding the release and movement of nutrients in this environment. In any such analysis it is essential that the 'opportunity time' or 'residence time' together with the availability of weatherable minerals be considered. Three conditions are suggested to account for the low solute concentrations in stream waters, each, any or all three of which may occur. (1) If there are no soil nutrients of importance then there can be supply neither to the river nor the plants. (2) If the residence time is too short relative to the equilibriation time of the minerals, then weathering and exchange may not occur. (3) If the residence time is too long (because rate of movement is slow), the 'turnover' will be small. In this context the analogy of an overflowing cup is discussed as a possible explanation of low solute concentrations. The results presented in the paper refer to the period 6th - 26thMay 1977, from a small hillslope-river segment at Resewa Ducke, Amazonas. Measurements made included soil tension, piezometric levels, river stage, infìltration rates and wetting front movement. Using Darcy's Law, water fluxes are determined. Draw down characteristics of the piezometers and river stage have been estimated using regressions of the logarithms of both these variables against the logarithm of time. The results suggest that during the period of observation the slope is almost saturated with respect to water. Actual saturation (positive pressures) are observed to occur at the foot of the slope under all conditions and within the slope during the earliest set of observations. Results from the computation of water fluxes indicate little lateral movement, the dominant flow is at or very close to vertical. Analysis of piezometer level and river stage suggests a very close link between the two, with only limited influence from the adjacent hillslope. In conclusion it seems that during the wet season, most of the river flow is generated by rapid rise beneath the floodplain and the slope immediately adjacent to the floodplain as a direct result of rainfall infiltration and that throughflow is unimportant. This is consistent with certain aspects of the cup analogy and goes far to explain the very low solute concentration found in the water of this and similar barrancos

On Waylen's regular axisymmetric similarity solutions

We review the similarity solutions proposed by Waylen for a regular time-dependent axisymmetric vacuum space-time, and show that the key equation introduced to solve the invariant surface conditions is related by a Baecklund transform to a restriction on the similarity variables. We further show that the vacuum space-times produced via this path automatically possess a (possibly homothetic) Killing vector, which may be time-like.Comment: 8 pages, LaTeX2

Changes in extreme rainfall events in South Africa

Extreme rainfall events can have severe impacts on society, so possible long-term changes in the intensity of extreme events are of concern. Testing for long-term changes in the intensity of extreme events is complicated by data inhomogeneities resulting from site and instrumentation changes. Using rainfall data from stations in South Africa that have not involved site relocations, but which have not been tested for inhomogeneities resulting from changes in instrumentation, a method of testing for changes in the intensity of extreme events is adopted. Significant increases in the intensity of extreme rainfall events between 1931–1960 and 1961–1990 are identified over about 70% of the country. The intensity of the 10-year high rainfall events has increased by over 10% over large areas of the country, except in parts of the north-east, north-west and in the winter rainfall region of the south-west. Percentage increases in the intensity of high rainfall events are largest for the most extreme events. While some inhomogeneities remain in the data used, the observed changes in the intensity of extreme rainfall events over South Africa are thought to be at least partly real

Cleft Care UK study. Part 5: Child psychosocial outcomes and satisfaction with cleft services

© 2015 John Wiley & Sons A/S. Objectives: To describe the impact of cleft service centralization on parental perceptions of child outcomes and satisfaction with care from the Cleft Care UK (CCUK) study and compare them to the Clinical Standards Advisory Group (CSAG) study that took place 15 years earlier. Setting and Sample Population: A subgroup of respondents from a UK multicentre cross-sectional study (CCUK) of 5-year-olds born with non-syndromic unilateral cleft lip and palate. Materials and Methods: Data on parents' perceptions of child self-confidence and their satisfaction with treatment outcomes and service provision were collected via self-report questionnaires. Data were compared with findings from the 1998 CSAG study. Results: Fewer parents in the CCUK study perceived their children as having poor self-confidence than in the 1998 CSAG study (8 and 19%, respectively). At least 81% of parents report satisfaction with the child's facial features after surgery and 98% report being satisfied with the care received. These results are similar to those reported in 1998. There is no evidence of an adverse impact on families' ability to attend appointments at the cleft clinic following centralization. Levels of reported problems (around 30%) with attendance were similar to those reported by CSAG. Conclusion: Centralization of cleft services appears to have improved parental perceptions of some child outcomes but has made little difference to already high levels of parental satisfaction with cleft care services. Centralization is not associated with an increase in the proportion of families who find it difficult to attend appointments

A qualitative exploration of attitudes to walking in the retirement life change

BACKGROUND: Walking is a simple activity that could help to reduce the prevalence of chronic diseases in all populations. Furthermore, an inverse dose–response relationship exists between steps taken and risk of premature death and cardiovascular events in middle-aged and older adults. There is a lack of information on how to effectively engage older adults around retirement age in walking. This qualitative study explored attitudes towards walking in older people with regard to habits, intensity, preferences and strategies for increasing walking behaviour. METHODS: In-depth qualitative interviews were conducted with 26 older adults who were either close to retirement or recently retired. An inductive thematic analysis was conducted. RESULTS: Three themes were identified from the data; 1) Engagement and perceived value of walking; was focused on the meaning of walking for the participant and the attributes they associate with their walking practice. 2) Integration and connectivity of walking; was focused on how participants integrate walking in their daily lives and whether walking can be practiced as a viable means of connectivity. 3) Strategies to increase walking; was focused on what factors motivate participants in their walking practice and what strategies they perceived to be beneficial to increase walking distance and intensity at an individual level. DISCUSSION: The views of walking in people of retirement age were represented within 3 key themes. The factors contained in these themes that may influence future walking practice are discussed with regard to future strategies to promote walking in the retirement life change. CONCLUSION: It may be beneficial to promote qualitative aspects of walking practice and strive for regularity rather than intensity of walking to accrue the social, psychological and intellectual benefits reported by individuals in the retirement life change. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-022-12853-2

Disease trajectories, place and mode of death in people with head and neck cancer: findings from the ‘Head and Neck 5000’ population-based prospective clinical cohort study

Background: Few large studies describe initial disease trajectories and subsequent mortality in people with head and neck cancer. This is a necessary first step to identify the need for palliative care and associated services. Aim: To analyse data from the Head and Neck 5000 study to present mortality, place and mode of death within 12 months of diagnosis. Design: Prospective cohort study. Participants: In total, 5402 people with a new diagnosis of head and neck cancer were recruited from 76 cancer centres in the United Kingdom between April 2011 and December 2014. Results: Initially, 161/5402 (3%) and 5241/5402 (97%) of participants were treated with ‘non-curative’ and ‘curative’ intent respectively. Within 12 months, 109/161 (68%) in the ‘non-curative’ group died compared with 482/5241 (9%) in the ‘curative’ group. Catastrophic bleed was the terminal event for 10.4% and 9.8% of people in ‘non-curative’ and ‘curative’ groups respectively; terminal airway obstruction was recorded for 7.5% and 6.3% of people in the same corresponding groups. Similar proportions of people in both groups died in a hospice (22.9% ‘non-curative’; 23.5% ‘curative’) and 45.7% of the ‘curative’ group died in hospital. Conclusions: In addition to those with incurable head and neck cancer, there is a small but significant ‘curative’ subgroup of people who may have palliative needs shortly following diagnosis. Given the high mortality, risk of acute catastrophic event and frequent hospital death, clarifying the level and timing of palliative care services engagement would help provide assurance as to whether palliative care needs are being met

Comparative studies on the structure of an upland African stream ecosystem

Upland stream systems have been extensively investigated in Europe, North America and Australasia and many of the central ideas concerning their function are based on these systems. One central paradigm, the river continuum concept is ultimately derived from those North American streams whose catchments remain forested with native vegetation. Streams of the tropics may or may not fit the model. They have been little studied. The Amani Nature Reserve in the East Usambara Mountains of north-eastern Tanzania offers an opportunity to bring these naturally forested systems to the attention of the ecological community. This article describes a comparison made between two lengths of the River Dodwe in this area. The work was carried out by a group of postgraduate students from eighteen European and African countries with advice from five staff members, as part of a course organised by the Tropical Biology Association. Rigorous efforts were made to standardise techniques, in a situation where equipment and laboratory facilities were very basic, through a management structure and deliberate allocation of work to specialists in each area.The article offers a summary of invertebrate communities found in the stream and its biomass. Crabs seem to be the key organism in both sections of the streams

Centralization of cleft care in the UK. Part 6:a tale of two studies

OBJECTIVES: We summarize and critique the methodology and outcomes from a substantial study which has investigated the impact of reconfigured cleft care in the United Kingdom (UK) 15 years after the UK government started to implement the centralization of cleft care in response to an earlier survey in 1998, the Clinical Standards Advisory Group (CSAG). SETTING AND SAMPLE POPULATION: A UK multicentre cross-sectional study of 5-year-olds born with non-syndromic unilateral cleft lip and palate. Data were collected from children born in the UK with a unilateral cleft lip and palate between 1 April 2005 and 31 March 2007. MATERIALS AND METHODS: We discuss and contextualize the outcomes from speech recordings, hearing, photographs, models, oral health and psychosocial factors in the current study. We refer to the earlier survey and other relevant studies. RESULTS: We present arguments for centralization of cleft care in healthcare systems, and we evidence this with improvements seen over a period of 15 years in the UK. We also make recommendations on how future audit and research may configure. CONCLUSIONS: Outcomes for children with a unilateral cleft lip and palate have improved after the introduction of a centralized multidisciplinary service, and other countries may benefit from this model. Predictors of early outcomes are still needed, and repeated cross-sectional studies, larger longitudinal studies and adequately powered trials are required to create a research-led evidence-based (centralized) service